The invention relates to a device for fracture-splitting a workpiece as it reads from the preamble of claim 1.
Known from U.S. Pat. No. 4,684,267 and EP 0 167 320 B1 respectively is a device for fracture-splitting a workpiece comprising several ring-shaped workpiece sections axially aligned in sequence, the device being provided with at least one expander means axially insertable into a bore formed by each of the ring-shaped workpiece sections and expandable at at least two expansion portions spaced away from each other axially. The expander means comprises an expanding mandrel featuring a plurality of expanding segments radially movable relative to the bore, whereby each expanding segment forms an expansion portion of the expanding mandrel. All expanding segments are to be actuated in common via an elongated actuating element extending in the interior of the expanding mandrel and coupled to a positioner located outside of the expanding mandrel. The actuating element comprises a plurality of wedge elements including first bevels extending at an angle to the axial direction assigned complementary to a plurality of second bevels likewise extending at an angle to the axial direction and each formed at an inner section of the expanding segments. Axial movement of the actuating element causes the first and the second bevels to cooperate, resulting in the expanding segments being extended to thus expand the expanding mandrel. This expander means enables all ring-shaped sections of the workpiece to be fracture-split simultaneously.
Devices of the aforementioned kind have, however, the disadvantage that their expander means is tailored to a specific workpiece geometry, i.e. in this case the position of the ring-shaped workpiece sections to be split and cannot be subsequently changed or adapted to another workpiece geometry, or only so at substantial production expense. Accordingly, a workpiece differing in configuration requires use of another expander means which substantial adds to the costs in having to produce these additional expander means as well as for their storage and maintenance.
The invention is based on the technical objective of providing a generic device which can be adapted to workpieces comprising ring-shaped workpiece sections to be split at differing positions by ways and means as simple and effective as possible.
The aforementioned technical objective is achieved by a device in accordance with the invention having the features as set forth in claim 1.
This device for fracture-splitting a workpiece comprising several ring-shaped workpiece sections axially aligned in sequence is provided with at least one expander means axially insertable into a bore formed by each of the ring-shaped workpiece sections and comprising at least one expander element expandable at at least two expansion portions spaced away from each other, the expander means being provided with an expansion control means integrated in and cooperating with the at least one expander element for controlling the variation in the position and/or extent and/or timing and/or sequence of expansion of the at least two expansion portions.
A workpiece comprising several ring-shaped workpiece sections axially aligned in sequence in the sense of the invention is understood to be a workpiece arrangement comprising a train of individual workpieces, each having but a sole ring-shaped workpiece section. It may also be a combination of the latter workpiece arrangement and one or more workpieces having several ring-shaped workpiece sections axially aligned in sequence. The integrated expansion control means is preferably configured purely mechanical substantially. However, the invention is not exclusively defined to this kind of configuration. The integrated expansion control means may also contain hydraulic, pneumatic, electromechanical, electrical, electronic or other suitable components as well as mixed forms thereof, all without departing from the scope of the invention.
Due to the expansion control means integrated in the device in accordance with the invention the expander means can now be adapted by simple and effective ways and means to workpieces having a differing number and/or differing position and/or differing configuration of the ring-shaped workpiece sections to be split. Unlike known prior art there is now no need with the device in accordance with the invention to produce a separate expander means for each of a large number of workpiece variants; this also eliminating the need for corresponding storage and/or maintenance thereof. Due to the integrated expansion control means the steps involved in adapting the device in accordance with the invention to each workpiece configured differing can be easily implemented by simple means, thus enabling the production and operating costs of a device in accordance with the invention to be reduced as compared to that of a conventional device. Apart from this, the device in accordance with the invention permits achieving greater flexibility in production which is especially of advantage in smaller series production. It is, however, further to be emphasized that by means of the integrated expansion control means of the expander means not only the position of the expansion portions of the expander means but also their extent and/or timing and/or sequence in expansion can all be variably controlled, resulting in the expander means now being multifunctional in performance whilst additionally enhancing the possibilities of varying production of the workpieces.
Further advantage aspects of the device in accordance with the invention are set forth in the subject matter of the sub-claims.
Preferred example embodiments of the invention including additional aspects and further advantages thereof will now be detailed with reference to the attached drawings.